Rim Fire and Yosemite National Park

Expansion of the Rim Fire day by day

Expansion of the Rim Fire day by day

Since I spent more than a month this summer writing fire briefing memos covering the major forest fires in Colorado, I’ve found that I’m much more aware of other fires in the news.  I also still prefer to go directly to the National Interagency Fire Center (NIFC) and Incident command (inciweb) websites to get my information rather than getting everything filtered through the news media.  I no longer have a Senator for whom to write fire briefings, so instead I’ll share my perspective with my family and friends as the first installment of “Dr. Pence WENT to Washington.”

Early on in a large fire, one of the details I watched for was obtaining an FMAG from FEMA.  I had always thought about FEMA more in terms of flooding, hurricanes, and tornadoes, and FEMA in those frameworks is most often a reactive agency.  During forest fires, however, FEMA has the ability to offer Fire Management Assistance Grants, or FMAGs.  The FMAGs provide federal financial assistance for fighting fires.  As of today, September 3rd, the cost to fight the Rim fire has risen to $72.3 million, so those financial resources are vitally important to the state.

Most fires start off small and thus are tackled by local resources.  California, with its extensive history of fires has a robust state-level resource called CAL FIRE.  Larger fires are much more complex to manage, so at some point in a mega-fire’s growth, the management will usually transition to one of the federal Incident Management Teams, with the Type 1 teams having the most expertise.  The Rim fire, which as of today is nearly 236,000 acres, is being managed by a unified command of CAL FIRE plus two Type 1 Incident Management Teams.  That’s an extremely large and complex fire, and indeed, it currently ranks as the fourth largest California wildfire since 1932 when records started becoming reliable.  The top three on the list were in 2003, 2012, and 2007, which shows the trend toward larger fires overall.

On this morning’s NIFC situation report, I was happy to see that the national preparedness level is back down to a 3.  Last week, it was up at 5, which is the highest level and indicated to me that national resources were being stretched to their limits.  Southern California remains at Level 4, but since the Rim fire is approaching 70% containment, some of the 5,000 people who were fighting the fire are being released to move onto other incidents, and resources are less constrained.

The Rim fire has simply been extremely challenging to fight.  The steep mountains of the Sierra Nevadas make it very difficult to get boots on the ground to cut fire lines, and since fire burns faster on inclines, safety of the fire crews must take precedent.  My experience from data analysis is that rapid expansion of fires is typified by two behaviors.  Crown fires, which convey fire through the tree canopies, tend to be very high intensity and can spread quickly.  Likewise spotting occurs when the wind throws burning embers forward of the fire perimeter like advance scouts so that new fires may start behind existing fire lines.  Fire retardant dropped by air tankers and by C-130 aircraft modified with MAFFS (Modular Airborne Fire Fighting Systems) has been critical in trying to control the growth of the fire and put out hot spots, but retardant is just one tool in the box.  Containment is achieved by creating fire lines that are devoid of fuel so the fire has nothing to burn.  For the Rim fire, this has been a combination of burnout operations where weather and terrain allowed for the execution of backfires to char a swath of trees and the fire encountering the string of lakes including the Hetch Hetchy reservoir.  If you look at the containment map, you can see the black containment lines around the bodies of water that are preventing the fires from spreading in that direction.

Black lines are containment.  Red lines are active and uncontained

Black lines are containment. Red lines are active and uncontained

From all my Colorado experiences, I know that getting the fire put out is only the first challenge.  Hetch Hetchy was a gorgeous valley that was dammed in 1923 to provide a reliable water supply for the thirsty city of San Francisco.  The Rim fire obviously can’t burn the water, but it can damage the water transfer infrastructure directly or through flooding and debris flows later.  Ash in the water either directly from the fire or from post-fire runoff down the steep mountain slopes may have a huge negative effect on the water quality as well.  In class this morning, I was talking about heterogeneous mixtures, and I brought in my souvenir bottle of water from the Colorado Springs reservoir a year after the Waldo Canyon fire.  I’ll include the picture just as a reminder of how bad the water can get.

In the upcoming year, I expect to hear the voices of the California Congressional delegation added to those of Colorado pointing out that prescribed burns to reduce the excessive fuel loads have been neglected too much as the huge cost of fighting fires pulls funds away from actually trying to prevent fires.  In 2002 in Arizona, the Rodeo-Chedeski fire burned 468,000 acres, which is about 60% the size of Rhode Island.  If you look at the burn map, the green areas were places that had undergone prescribed burns in the previous 10 years.  Those areas were not extensive enough to stop the advance of the fire, but the fire in those spaces stayed on the surface rather than jumping to the crowns, and the intensity was considerable less than untreated areas.  Unfortunately, in addition to the cost required to plan and execute prescribed burning, on rare occasions prescribed burns have escaped and turned into large fires themselves.  Also, air quality restrictions designed to improve people’s health are often counter to prescribed burns and their resulting degradation in air quality from the smoke.  Thus an additional impediment is created where one benefit must be sacrificed for another.

Rodeo-Chedeski Fire, 2002

Rodeo-Chedeski Fire, 2002

At this point, the prognosis for the Rim fire is looking good.  Sprinklers and clearing brush has helped to protect two groves of giant sequoias in Yosemite, and on the western side of the fire, firefighters have protected millions of dollars of power lines and electrical substations.  It’s still going to be a long two and a half weeks before they expect to have full containment, but the fire teams do seem to be over the hump and the weather has been cooperating.  I always have mixed emotions about big forest fires.  I don’t like all of the destruction, but I’m also fascinated by everything I’ve learned and how much interpretation I can do from the data available on the web.

Intersection of the Rim fire and Yosemite National Park from several days ago

Intersection of the Rim fire and Yosemite National Park from several days ago


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